Hysteroscopic Transillumination as a Guide for Laparoscopic Excision of Rudimentary Uterine Horn: A Winning Duo.

STUDY OBJECTIVE: Anatomic anomalies of the female reproductive genital tract affect approximately 5.5% of women [1]. The hemiuterus or class U4 by the European Society of Human Reproduction and Embryology / European Society for Gynaecological Endoscopy 2013 classification is a rare congenital malformation defined as a unilateral uterine development, with a contralateral part that could be either incompletely formed or absent. This class is divided into 2 subclasses depending on the presence or not of a functional rudimentary cavity (U4a/U4b) [2]. This work aimed to share our experience performing an hysteroscopic and laparoscopic combined technique to surgically manage this uterine malformation exploiting the hysteroscopic transillumination. DESIGN: A step-by-step explanation of surgical technique with narrated video footage. SETTING: Tertiary Level Academic Hospital "IRCCS Azienda Ospedaliero - Universitaria di Bologna" Bologna, Italy. INTERVENTIONS: A 32-year-old woman with a symptomatic (severe dysmenorrhea and chronic pelvic pain) suspected U4a uterine malformation diagnosed at our center was scheduled for laparoscopic removal of the right uterine horn and ipsilateral salpingectomy exploiting the contemporary hysteroscopic transillumination guidance. We selected this approach to avoid possible complications owing to the anatomic anomalies that are very common in these cases [3,4]. After coagulation and section of the right round ligament at the uterine angle and opening of the right broad ligament, access to the retroperitoneum was obtained to directly visualize the entire course of ureter and the uterine artery. The right uterine artery was coagulated and sectioned at the uterus. Then, the hysteroscope was introduced to the uterine fundus and the light source brightness was increased up to 100% to allow an adequate transmural visualization of the uterine defect from the laparoscope. Once the defect edge was well highlighted, the right uterine horn was isolated and removed using a monopolar hook, taking care to preserve an adequate amount of myometrium. A double layer running suture with barbed absorbable thread (V-Loc) for reconstructive purposes was performed. The specimen was retrieved inside an endobag to allow a safe extraction. Right salpingectomy was then performed. CONCLUSION: Considering the great anatomic variability of this condition, this type of surgery is not always simple. Indeed, the borders between the uterus and the rudimentary uterine horn are often not perfectly recognizable; this can lead to accidental removal of healthy myometrium and increase the risk of perioperative bleeding [5]. In our experience, the combined hysteroscopic and laparoscopic combined technique allows the surgeon to better delimit the borders of the hemiuterus, providing a more conservative and safer surgery. Hysteroscopic transillumination offers the possibility to modulate the radicality in the resection of the rudimentary horn and in the final treatment of dysmorphism.

Bilateral acute iris transillumination (BAIT) syndrome: Differential diagnosis based on clinical, OCT and UBM findings.

INTRODUCTION: Bilateral acute iris transillumination (BAIT) is a relatively new syndrome whose etiopathogenesis is still not fully understood. It is characterized by acute bilateral onset of intense pigment dispersion in the anterior chamber, iris depigmentation with severe transillumination defects, accentuated pigment deposition in the angle, and elevated intraocular pressure (IOP). In literature, the first case was of bilateral acute iris depigmentation (BADI) reported in 2004 in a 77-year-old woman. In 2019, Perone et al. published a review about BAIT syndrome. They reported a total of 79 cases have been published up that date, mainly in Europe and especially in Turkey and Belgium. The majority of reported cases were of bilateral acute iris depigmentation (BADI). BAIT syndrome might be mainly confused with acute iridocyclitis, acute primary angle-closure (APAC) and pigment dispersion syndrome (PDS). In relation to BAIT, controversies still exist regarding the etiology being the differential diagnosis of paramount importance for adequate treatment. PURPOSE: To report a case of BAIT syndrome associated to refractory glaucoma and to discuss the differential diagnosis based on clinical, OCT and UBM findings. METHODS: We present a case of BAIT syndrome in which clinical, OCT and UBM findings have pointed out the similarities and, mainly the diagnosis differences with other ocular diseases. CONCLUSIONS: BAIT syndrome with accentuated IOP rise must be differentiated of other ocular diseases. It requires urgent clinical therapy and/or surgical management as occurred in the present case for avoiding structural damage in OCT and visual field loss. OCT and UBM are critical for early recognition, differential diagnosis and management.

Temporomandibular Joint: Approach to the Intermediate Space by Triangulation With Transillumination Reference.

Arthroscopy of the temporomandibular joint is a minimally invasive surgical procedure. Nowadays, 3 levels are described depending on the complexity. Level I involves a single puncture with an anterior irrigating needle for outflow. Level II involves a double puncture using triangulation in order to be able to perform minor operative maneuvers. Subsequently, it is possible to progress to Level III and perform more advanced techniques, through multiple punctures, involving the arthroscopic canula and 2 or more working cannulas. However, in cases of advanced degenerative pathology or re-arthroscopy, it is common to observe advanced fibrillation, severe synovitis, adhesions, or articular obliteration which makes conventional triangulation difficult. On these cases, we propose a simple and effective technique that facilitates approach to the intermediate space by means of triangulation with transillumination reference.

Transillumination of an Anterior Fontanelle Dermoid Cyst.

Dermoid cysts are slowly growing benign lesions of ectodermal tissue that often occur in the anterior fontanelle. Clinicians often rely on a negative transillumination test to begin the process of correctly diagnosing a dermoid cyst. However, here the authors present a case of a 7-month-old girl who presents with a transilluminating dermoid cyst.

Bilateral Acute Iris Transillumination and Elevated Intraocular Pressure After COVID-19 Infection.

Bilateral acute iris transillumination (BAIT) is characterized by abundant pigment discharge into the anterior chamber. Atonic pupil and severe intraocular pressure (IOP) elevations may be observed. Generally, there is a viral upper respiratory tract infection or systemic fluoroquinolone usage before BAIT. Two cases with a recent history of coronavirus disease 2019 (COVID-19) presented with a complaint of decreased vision. Elevated IOP and iris transillumination defects were observed in both patients. Both patients were diagnosed with BAIT. Although elevated IOP was controlled with medical treatment in 1 patient, glaucoma surgery was performed in the other patient because it could not be controlled with medical treatment. As both patients received no systemic treatment for COVID-19, the pressure rise seems to be directly related to the viral infection alone through the inflammatory process. Atypical ocular presentations of COVID-19 should be kept in mind as it can have serious consequences.

Comparison of LED-Based Transillumination Device with Traditional Vein Viewing Methods for Difficult Intravenous Cannulation in Indian Children: A Nonrandomized Controlled Trial.

OBJECTIVES: To compare the utility of transillumination device with traditional vein viewing in situations with difficult peripheral venous access in pediatric patients. METHODS: This was a nonrandomized, controlled trial. All the children aged between 3 to 36 mo admitted in tertiary care referral hospital, who satisfied difficult intravenous access (DIVA) score of equal to or more than 4 were included in the study. The children were assigned to transillumination device group (intervention) and traditional vein viewing group (traditional). The proportion of successful cannulation in the first attempt and median number attempts required to successfully cannulate in each group were estimated. RESULTS: A total of 509 children were included in the study. The proportion of single attempt cannulation was significantly higher in the intervention group as compared to traditional group (p value = 0.001). The median number of attempts to successfully cannulate was found to be significantly less in the interventional group (median 1 vs. 2; p value = 0.001). On bivariate analysis, use of transillumination device was found to have a 2.64 times higher likelihood to successfully cannulate in the first attempt. CONCLUSION: The use of transillumination device significantly improves the first attempt success rate and number of attempts for successful cannulation.

A Novel Method for Transillumination.

PURPOSE: To introduce a cost-efficient device for transillumination in the management of uveal melanoma. METHODS: Todorich Illuminated Depressor is a ball-point depressor, designed to work with the 23-, 25- and 27-gauge Alcon Constellation endoillumination. It was invented to allow indentation and peripheral vitreous visualization for vitrectomy. RESULTS: Todorich depressor combined with endoillumination can also work as a device for transillumination for tumor localization. We started using this method of transillumination for the management of uveal melanomas since September 2020 and have successfully performed Ru-106 plaque brachytherapy for 10 cases of uveal melanoma. Three were large choroidal melanoma cases, and en bloc tumor resection by partial lamellar sclerouvectomy was successfully performed after precise localization of tumors using this method. CONCLUSION: Alcon Constellation endoillumination capped with Todorich Illuminated Depressor is an affordable and viable alternative for transillumination of intraocular tumors.

Bilateral Acute Depigmentation of Iris (BADI) and Bilateral Acute Iris Transillumination (BAIT)Following Acute COVID-19 Infection.

PURPOSE: To report the presenting features and outcomes in patients who developed bilateral acute iris transillumination (BAIT) or bilateral acute depigmentation of iris (BADI) following acute COVID-19 infection. METHODS: Thirty two eyes of 16 patients were reviewed retrospectively. The severity of COVID-19 infection, use of antibiotics, time of onset of ocular symptoms; ocular signs, the course and surgical procedures were recorded. RESULTS: 24 eyes of 12 BAIT and eight eyes of four consecutive BADI patients were included. The mean time between infection and onset of ocular symptoms was 2.5±1.1 weeks. Nine patients were treated with oral moxifloxacin for COVID-19 prior to presentation. Trabeculectomy was performed in 7 eyes (21.8%) of 5 BAIT patients; in the postoperative follow-up, IOP was controlled without medication in 6 eyes, with medication in 1 eye. CONCLUSION: BADI and BAIT can also develop after COVID-19 infection. A significant proportion of BAIT patients may require glaucoma surgery.

Reconstructing a Deblurred 3D Structure in a Turbid Medium from a Single Blurred 2D Image-For Near-Infrared Transillumination Imaging of a Human Body.

To provide another modality for three-dimensional (3D) medical imaging, new techniques were developed to reconstruct a 3D structure in a turbid medium from a single blurred 2D image obtained using near-infrared transillumination imaging. One technique uses 1D information of a curvilinear absorber, or the intensity profile across the absorber image. Profiles in different conditions are calculated by convolution with the depth-dependent point spread function (PSF) of the transillumination image. In databanks, profiles are stored as lookup tables to connect the contrast and spread of the profile to the absorber depth. One-to-one correspondence from the contrast and spread to the absorber depth and thickness were newly found. Another technique uses 2D information of the transillumination image of a volumetric absorber. A blurred 2D image is deconvolved with the depth-dependent PSF, thereby producing many images with points of focus on different parts. The depth of the image part can be estimated by searching the deconvolved images for the image part in the best focus. To suppress difficulties of high-spatial-frequency noise, we applied a noise-robust focus stacking method. Experimentation verified the feasibility of the proposed techniques, and suggested their applicability to curvilinear and volumetric absorbers such as blood vessel networks and cancerous lesions in tissues.

Transillumination Techniques for Vessel Identification During Small Colon Resection in Six Horses.

BACKGROUND: Transillumination has been described in human surgery to improve vessel visualization but has not been described in horses. Since the equine mesocolon contains a great amount of fat which restricts visualization of the vessels, this technique could be useful during small colon resection. OBJECTIVES: To describe transillumination of the mesocolon to provide an improved vessel identification during resection and anastomosis of the small colon in horses. METHODS: Data of horses that underwent resection and anastomosis of small colon were recorded. Two transillumination techniques were used during resection and anastomosis of small colon. In a first technique, used on three horses, the operating lamp was used. It was lowered and tilted so that the assistant surgeon could lift the small colon so that the mesentery was between the lamp and the first surgeon eyes. In a second technique, used on further three horses, a smartphone with a rear LED flashlight turned on was placed into a sterile rectal sleeve. The device was placed on the surgical field and the portion of small colon to be resected was then laid over the smartphone, to backlight the vessels. The vessels were then identified and ligated. RESULTS: Six horses referred for acute colic that underwent resection and anastomosis of the small colon were included in the study. Using both transillumination technique the mesocolon was backlit and the vessels were clearly and easily identified, dissected, ligated, and transacted without complications. The smartphone technique subjectively ensured a better operating position for the surgeon and less fatigue for the assistant. CONCLUSIONS: Transillumination techniques are useful to avoid damage when ligating vessels and using the flashlight of a smartphone is easier and provide safer and more accurate transection of them during small colon resection and anastomosis.

Histological analysis of an alkaline based tissue clearing technique for fetal musculoskeletal tissue / Análisis histológico de una técnica de limpieza de tejido de base alcalina para tejido musculoesquelético fetal

SUMMARY: Tissue clearing techniques are frequently used in the observation and description of anatomical structures and pathways without altering the three-dimensional layout of the anatomical specimen. Tissue optical clearing promotes preservation of three-dimensional structures, which allows the study of the internal anatomy in its original position and original spatial interaction. Among these techniques, Potassium Hydroxide (KOH) maceration clearing is one of the most widely used. However, the histological changes of tissue after KOH maceration have yet to be fully understood. Our aim is to describe the microscopical differences between macerated and normal tissue. To better understand said changes, two human fetuses with a gestation period of 16 to 28 weeks were cleared and processed for histological analysis. Microtome slides of the fetuses' lower limbs were obtained and stained with Hematoxylin & Eosin, Periodic Acid Schiff (PAS), and Masson's trichrome with the purpose of observing the histological and macromolecule composition changes in cleared tissue. Remarkable differences at a histological level regarding the composition of the cellular structures, since diaphanized tissues showed a predominance of extracellular matrix composed of collagen fibers with the absence of most of the nucleated cellular tissue. Phospholipid's saponification, nucleic acids degradation and a change on proteins structural properties are the main factors inducing clearing. At the same time, molecular stability of collagen in alkaline conditions allows the specimen to maintain its shape after the process.

RESUMEN: Las técnicas de limpieza de tejido se utilizan con frecuencia en la observación y descripción de estructuras y vías anatómicas sin alterar el diseño tridimensional de la muestra anatómica. El aclaramiento óptico de tejidos promueve la preservación de estructuras tridimensionales, lo que permite el estudio de la anatomía interna en su posición original y la interacción espacial original. Entre estas técnicas, el aclarado por maceración con Hidróxido de Potasio (KOH) es una de las más utilizadas. Sin embargo, los cambios histológicos del tejido después de la maceración con KOH aún no se han entendido por completo. Nuestro objetivo es describir las diferencias microscópicas entre el tejido macerado y el normal. Para entender mejor dichos cambios, dos fetos humanos con un período de gestación de 16 a 28 semanas fueron aclarados y procesados para análisis histológicos. Se obtuvieron microtomos de las extremidades inferiores de los fetos y se tiñeron con hematoxilina y eosina, ácido peryódico de Schiff (PAS) y tricrómico de Masson con el fin de observar los cambios histológicos y de composición de macromoléculas en el tejido aclarado. Diferencias notables a nivel histológico en cuanto a la composición de las estructuras celulares, ya que los tejidos diafanizados mostraban un predominio de matriz extracelular compuesta por fibras de colágeno con ausencia de la mayor parte del tejido celular nucleado. La saponificación de los fosfolípidos, la degradación de los ácidos nucleicos y un cambio en las propiedades estructurales de las proteínas son los principales factores que inducen la depuración. Al mismo tiempo, la estabilidad molecular del colágeno en condiciones alcalinas permite que la muestra mantenga su forma después del proceso.

Penlight versus Smartphone: Diagnostic Efficacy of Transillumination.

Background: The purpose of this study was to compare the diagnostic accuracy of a smartphone flashlight to a conventional penlight with regards to transillumination of simulated soft tissue masses of the hand and wrist. Methods: Eight participants performed transillumination assessments in a fresh frozen cadaver upper extremity model. Spheres measuring 9.5 mm were used to simulate fluid-filled or solid soft tissue masses. Two spheres were placed on the volar aspect and two on the dorsal aspect of the wrist. These were then evaluated with either a smartphone flashlight or penlight. Participants noted whether each sphere did or did not transilluminate. Each participant performed two evaluations at an interval of 3 weeks. Results: The overall sensitivity, specificity and accuracy of the smartphone were 100%, 44% and 72%, respectively. The overall sensitivity, specificity and accuracy of the penlight were 100%, 75% and 88%, respectively. The difference in accuracy between the smartphone group and penlight group was statistically significant (p = 0.029). The kappa value, indicating intra-observer agreement, for the smartphone group and penlight group was 0.76 and 0.76, respectively. Conclusion: In conclusion, transillumination with a penlight is a viable adjunct to the examination of soft tissue masses of the hand and wrist. The use of a smartphone flashlight, while convenient, is less accurate than a penlight and can lead the examiners to misinterpret the composition of soft tissue masses. Level of Evidence: Level IV (Diagnostic).

Unilateral acute iris transillumination like syndrome following intracameral moxifloxacin injection.

PURPOSE: To describe a case of bilateral acute iris transillumination (BAIT)-like syndrome following intracameral moxifloxacin injection after cataract surgery. METHODS: A case report. RESULTS: We report a case of unilateral acute iris transillumination and distorted pupil in a 53-year-old male who underwent uneventful cataract extraction with intracameral moxifloxacin. CONCLUSION: BAIT-like syndrome may be a rare side effect of intracameral moxifloxacin.

In vivo analysis of endocanalicular light pipe transillumination in endoscopic dacryocystorhinostomy: Anatomic considerations and cautions for the transitioning.

PURPOSE: Localization of the lacrimal sac is a critical step during endoscopic dacryocystorhinostomy (endo-DCR). A "light pipe" can be used to transilluminate the lacrimal sac endonasally. We hypothesized that this may misguide the surgeon learning endo-DCR to create an osteotomy mostly posterior to the maxillary line if only the bone overlying the transillumination was to be removed, as the thinner lacrimal bone will transmit light more readily than the thicker maxillary bone of the frontal process of the maxilla that forms the anterior lacrimal sac fossa. METHODS: The charts of 32 patients with primary acquired nasolacrimal duct obstruction in whom a lighted system was used during endo-DCR at Massachusetts Eye and Ear from April 2015 through October 2016 were reviewed. Patients with prior history of lacrimal surgery or trauma directly to the lacrimal sac fossa were excluded. Location of the maximal point of transillumination in relation to the maxillary line was observed and noted intraoperatively. RESULTS: Of a total of 39 endo-DCR surgeries performed, the intraoperative transillumination point was entirely posterior to the maxillary line in 32 instances (82%). CONCLUSIONS: Use of an endocanalicular light pipe preferentially illuminates posterior to the maxillary line endonasally. The anterior lacrimal sac fossa (maxillary line and anterior as visualized endonasally) is rarely transilluminated, likely due to thicker bone in that region. Surgeons learning how to perform endo-DCR using a light pipe should be aware of this phenomenon.

Firefly® System and Organ Transillumination in Robotic Gynecologic Surgery.

BACKGROUND AND OBJECTIVES: Near-infrared fluorescence (NIRF) of the Firefly® system has become a useful and widespread technique for the visualization and detection of tumors, sentinel lymphnodes, and vascular/anatomical structures. METHODS: Between February 1, 2017 to September 30, 2019, a total of 25 patients affected by benign and malignant pathologies underwent robotic surgery by the use of organ transillumination with the concomitant Firefly®. We analyzed the pre-operative patients' characteristics (age and body mass index [BMI], previous abdominal surgeries and systemic disease); pre-operative diagnosis, surgical procedure and approach (multiport or single site), transilluminated organ, surgical outcomes (operating time, incidence of intraoperative complications, and incidence of conversion to other surgery); and postoperative outcome. The surgical procedures included: four bladder endometriosis nodules resections, one pelvic lymphadenectomy with ureterolysis, and 23 hysterectomies. RESULTS: The average operating time was 283.3 (+/- 76.9) minutes, there were no intra-operative complications or laparotomic conversions. The average recovery days were 5.9. There have been three grade 2 post-surgical complications, following the Memorial Sloan Kettering Cancer Center Surgical Secondary Events System classification. The combination of NIRF and transillumination allows a clear view of the anatomical landmarks and the resection margins. CONCLUSIONS: It's likely that improvement in the anatomical detail could confer a greater surgical safety with lower percentage of intra and post-surgical complications and sparing of safe tissue. To evaluate the validity of these techniques in a larger number of patients and compare these new surgical procedures with standard ones, further studies are needed.

Near-infrared Transillumination and Photodynamic Therapy Using Hypericin in Animal Laryngeal Tumors.

BACKGROUND: We aimed to validate a pilot study of photodiagnosis using near infrared (NIR) transillumination and assess the clinical efficacy of hypericin-mediated photodynamic therapy (HYP-PDT) in a rabbit laryngeal cancer model in order to develop a novel therapeutic modality with complete remission and preservation of the functional organ. METHODS: (1) In vitro study: VX tumor cells were subcultured and subjected to HYP-PDT. (2) In vivo study: A laryngeal cancer model was developed in which 12 rabbits were inoculated with a VX tumor suspension in the submucosal area of the left vocal fold using a transoral approach. All rabbits underwent NIR transillumination using light with a wavelength of 780 nm. The survival periods of the three treatment groups (6 rabbits in Group A: HYP-PDT, 3 each in Groups B and C: laser irradiation or HYP administration only) were analyzed. RESULTS: The higher the HYP concentration, the lower the VX cell viability in response to HYP-PDT using 590 nm LED. Following HYP-PDT, small tumors in Group A-1 rabbits healed completely and the animals demonstrated a long survival period, and larger tumors in Group A-2 healed partially with a survival period that extended over 3 weeks after inoculation. The survival of Groups B and C were not different over the first 3 weeks of the study, and were shorter than in Group A. CONCLUSION: We found HYP-PDT could be a curative therapy for early-stage cancers that may also preserve organ function, and may inhibit tumor progression and metastasis during advanced stages of laryngeal cancer.

TrueVue transillumination volume rendering for three-dimensional transoesophageal echocardiography in interventional imaging.

AIMS: The aim of the present article is to address the advantages of real-time TrueVue transillumination rendering for three-dimensional transoesophageal echocardiography in the context of echocardiographic procedural guidance for structural interventions for several procedural concerns. METHODS: Procedures in which transillumination imaging was used during at least one step of the whole intervention were retrospectively collected; the loops were reviewed by an experienced imaging specialist and the most important concerns imaged in the loops were listed. The apparent added value of transillumination for each of these concerns was scored independently by two imager specialists, and their agreement was derived. RESULTS: Between January and June 2019, 50 procedures were performed in our centre. Transillumination imaging was used in 64% of these cases. Considering all the loops the added value of transillumination compared with the conventional rendering was scored greater than 3 in a Likert scale in 87% of analysed loops by both the operators with a good agreement (κ  = 0.47, P  = 0.001). A different level of perceived advantage and agreement was observed between three image features that improved: substantial agreement (κ  = 0.652, P  = 0.001) for enhancing the contrast between structures and cavities (n  = 24 loops); good agreement for the contrast between different structures (κ  = 0.588, P  = 0.002) (n  = 37 loops); moderate agreement for the perception of interaction between the device and structures (κ  = 0.3, P  = 0.027) (n  = 7 loops). CONCLUSION: The use of new volume-rendering techniques in interventional imaging may be useful especially for solving the concerns regarding the cavity-structure contrast.

Capacidad de sellado de los conductos laterales con distintas técnicas de obturación del conducto radicular / Sealing capacity of lateral canals with different root canal obturation techniques

Objetivo: Estimar y comparar la eficacia de diferentes técnicas de obturación para impedir el flujo de colorante a través de los conductos laterales. Materiales y métodos: Se emplearon 50 premolares inferiores extraídos y conservados en formol neutro al 5% hasta el momento de su uso, a los cuales se les realizaron conductos laterales artificiales. Una vez instrumentados los conductos principales, los dientes fueron divididos al azar en 5 grupos (n=10) para ser obturados con cuatro técnicas distintas: A) System B + inyección de gutapercha termoplástica del sistema Elements, Extruder; B) obturadores de Thermafil, ProTaper Universal; C) técnica híbrida y D) obturación con inyección de gutapercha termoplástica del sistema Elements, Extruder. Inmersos en tinta china y diafanizadas las raíces, se evaluó la longitud de penetración de la tinta en los conductos laterales. Se empleó el análisis de la varianza para detectar diferencias significativas (P<0,05) entre los niveles medios de penetración del colorante según las técnicas de obturación y las zonas del diente, y se efectuaron pruebas de rango múltiple (HSD de Tukey) para realizar comparaciones dos a dos, manteniendo fija la tasa de error por familia. Resultados: A la técnica B le correspondió el valor medio más bajo (30,63%) de penetración de tinta china. Los valores medios más elevados (54,52% y 51,74%) correspondieron a las técnicas A y C, respectivamente. Conclusión: Ninguna de las técnicas de obturación del conducto radicular empleadas ha sido capaz de impedir la filtración del colorante en los conductos laterales (AU)

Aim: To estimate and compare the different obturation techniques to avoid the flow of colorant through lateral canals. Materials and methods: 50 extracted lower premolars preserved in 5% neutral formol until the moment of use, had artificial lateral canals made. Once canals were instrumented, the teeth were randomly divided into 5 groups (n=10) to be filled with four different techniques: A) System B + injection of thermoplastic gutta-percha, Elements system, Extruder; B) Thermafil, ProTaper Universal obturators; C) hybrid technique, and D) injection of thermoplastic gutta-percha, Elements system, Extruder. Having immersed the premolars in India ink and diaphanized the roots, the penetration length of the India ink inside the canals was assessed. Analysis of variance was used to detect significant differences (P<0.05) between the mean levels of dye penetration according to the filling techniques and tooth areas, and multiple range tests (Tukey's HSD) were performed for two-to-two comparisons, keeping the error rate per family fixed. Results: Technique B had the lowest mean value (30.63%) of penetration. The highest mean values (54.52% and 51.74%) corresponded to techniques A and C, respectively. Conclusion: No obturation technique of the root canal used was able to avoid filtration of colourant in the lateral canals (AU)